To increase the power of an internal combustion engine, it is known for the latter to be supercharged by virtue of the mixture for combustion being compressed before being supplied into the combustion chamber. Furthermore, it is already generally known that, to perform the compression, use may be made of energy which is extracted, by way of a turbine, from an exhaust-gas flow of the internal combustion engine or which is supplied by way of an electric motor. Whereas the former possibility gives rise to an undesired lag in the response behavior of the internal combustion engine, in the latter case electrical energy is extracted from an on-board electrical system battery of the vehicle, whereby the battery and the on-board electrical system can be subjected to intense load in an undesired manner.
The document WO 2008/020184 A1 describes a motor vehicle air blower in the case of which, by way of a planetary mechanism, the rotational speed of an internal combustion engine is added to the rotational speed of a first electric machine, while a second electric machine is likewise driven by the internal combustion engine in order to generate the electrical current for the first electric machine. The planetary mechanism adds the two mechanical powers of the internal combustion engine and of the first electric machine, wherein a compressor is operated, with this combined mechanical power, at high rotational speed. It emerges from the cited document that the planetary mechanism is provided between the two electric machines, and furthermore, the two electric machines and the planetary mechanism are accommodated in the same housing.